Gas-furnace.



0.1. KUENHOLDl GAS FURNAGE. APPLICATION FILED SEPT-6. |910. RENEWED OCf. 18,1915.

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Patented Nov. 23, 1915.

0.1. KUENHOLD.

GAS FURNACE. l APPLICATION FILED SEPT.6. 1910. IIENEwED ocT. 18. I9I5.

l 1 61 ,776. Patented Nov. 2,3, 1915.

2 SHEETS-SHEET l2.

6.71% l om I Lawn/d) barra sraras raranr carica.

OTTO J'. KENHOLD, OF CLEVELAND, OHIO.

GAS-FURNACE.

Specification of Letters Patent. Patented NOV. 23,1915.,l

Application filed September 6, 1910, Serial No. 580,530.' Renewed October 18, I1915. Serial No. 56,612.

To all whom t may concern Be it known that I, OTTO J. KUENHOLD,

citizen of the United States, residing at.l

complete combustion along with the most` practical application of theheat possible to theexposed surfaces, a desideration always in heating systems but seldom fully attained.

Specifically claim for my invention,--

y F irst,-thorough mixture of the air' and gases to promote complete combustion.

Second, the proper proportion of air, particularly providingagainst a large surplus air supply as this would be very injurious for the following reasons It dilutes the mixture thereby preventing complete coinbustion; it cools the flame below the ignition point of some'of the constituent gases; it cools the. inner surfaces of the-boiler or furnace; it absorbs 4heat and carries it up the chimney.V y i I Thirdfatfords an equal distributiony of the circulation so that all the heat absorbing andltransmitting surfaces do a fair share of wor r.

Fouitli,-tlie bringing of the temperature .shown by the arrows Fig. 1.

of the Haine up to ashigh a point as possible so that every particle of tlie mixture is raised to or beyond its ignition point.`

l `ifth,-providing a liberal combustion chamber above the-burners so that combustion is entirely completed before the products come in contact With any cooling surfaces, such as water tubes, and other heat absorbing parts.

Sixth, a thorough insulation so that the heat generated does not escape except as it is absorbed into the water or air to be heated within the furnace. y K

Seventh,-making all parts simple, substantial, and easily removable or accessible` for repairs.

In the accompanying drawings, Figure 1 is a longitudinal sectional elevation of the furnace showing the general air and Smoke `circulation as applied to a certain hot water boiler which is the subject matter of an` application for Letters Patent concurrent herewith in the yPatent Oliice and .bearing Ser.

No. 580,999, filed September 6, 1910. Fig. 2 isa transverse section on line a-a, Fig. l, showing the individual burner compartments and the combustion chamber. Fig. 3 is a horizontal section or plan on line Zl-b, Fig. l, and showing the burner compartments in three Several conditions as hereinafter .fully Idescribed. Fig. 4L is a perspective view of one of the burners. Fig. 5 is a detail of the burner and grate lifter. Fig. 6, Sheet 2, shows an enlarged longitudinal section through one of the burner compart- Y ments with a complete equipment of grate and other parts for dierent kinds of fuel. Fig. 7 is a horizontal section on the line e-e of Fig. 6, through the mixer of one of Y the burner compartments and particularly shows the controlling devices for ,the air and gas supply to burners.` Fig. 8 is a section on line cZ-CZ, of Fig. 6.

The furnaceas thus shown is adapted especially for a hot water heating system for residences and the like, but it may kalso be utilized for the generation'of steam, and. is fprovided with an air intake chamber A, an ashpit or bottom portion beneath the hard fuel grate whichis sub-dividedinto three several chambers B, B and B front to rear into which the air passes froml chamber A for the combustion of whatever kind of fuel is used.

The circulation of the air and gases is |The air is taken in through the screened opening l: at the rear of the furnace into the air intake chamber A and passes through this into the series of burner compartments B, B, B

through vopenings 2 in the intervening wall andwhich may be opened oi' closed or regulated by means of vdoors or dampers 3. Each of these said burner compartments contains a burner G complete with a mixer v7 whichv curves upward and the burner opens at its topinto a combustion chamber C common to all said burner compartments or chambers.

Over each compartment or chamburners to afford upward draft from beneath, the products passing thence upward into and through the so-called heater compartment D.

The heater compartment D is utilized ffor heating'the water, andwhile this part of the 'furnace does not come within this application I may say that I employ anumber of hollow water circulating units on castings (not shown) and arranged side l'by side and adapted to be connected together at I and O respectively similar to a cast iron radiator, the exterior surfaces of each unit being of such shape thatwhenA so assembled a series of horizontally inclined smoke flues 66 are left between the said units, and also vertical smoke passages 50a/and 64at the front and, rear respectively and with which the flues 66 communicate. Suitable walls 46, 47 and 48 meet and close the heater chamberD, at

the top, back and bottom, and a removable cover 36 closes. the front. The outermost units .form the sides, so that the entire `heater chamber D is 'inclosed'except for` smoke`in lets 50 at the frontand outlets 64 at the back and openings 49 at the lower rear for purposes later lset forth.

` The structure thusdescribed may be varied,

the essential point being. that there is a chamber Dover the chambers A and C through which the products of combustion passiand wherein heatng'is accomplished.

After the vfuel is completely consumed or i burned up the products pass from Acombus- 35 `tion chamber C upward through passages 50, flues 66 and outlet passages 64 into the transverse hood 41 and out at E to the chimneybymeans of pipe 40. The damper 38 above 1n conjunction with doors 3 below gives-perfect control of the draft and air supply. The outlet lpipe 40 fits within instead of-without a thimble 67 cast on. the

hood 41. This -isl tovcause the drippingsor condensation to run into the lstructure 1n-' stead of over the outside as is generally the -case with them. An annular flange' 39y on l the inside of the smoke outlet passage E facts as a stop for the smoke pipe. The dripil pings from the smoke pipe 40 as well as any other drippings drop through openings 49 between the water heating7 units above described but notshown into the pan P from which they are drained by means of lpipe 43. o

Door 42 givesaccess to the pan. This pan is of metal and completely covers and sepaparts above or overythe same.` 'A partition 33, separates chambers A and C and considerable heat radiates through this partition and through the pan P into 'the air intake chamber A,

thus` preheating the air supply to the several burner compartmentsB, B, B. vThere 'is also considerable downward radiation within the burner compartments from the lire,

and this, in `addition to the preheating of lney, and has other dis the air'in the intake chamber A provides a highly heated air supply to the mixers through air intakes 66 and to the flames as well. This is a distinct advantage, as it promotes a high temperature of combustion.

The relatively large combustion chamber plate or woven wire screen 68 is placed in the burner as shown in Fig. 6, and the gases must pass through this screen to the exit jets or holes. The further use of this plate is to prevent backring of the burner or the ignition-of the gas jet which shoots the raw gas into the mixer, It is necessaryto take some such steps to prevent such backiring with a construction in which heated air is fed to the mixer andin which the burner becomes very hot (sometimes red hot in my case). I rely `principally upon careful proportioning of the mixer, burner and other associated parts to avoid the backiring but prefer to add this screen as an additional preventive. It also gives 'a more equal flame over the burner because it equally distributes the gas beneath the same to all parts of the burner.

I may observe that in general the obtain- `ing of a `thorough intermixture of the air and gas is a matter of proper proportion and careful design rather than of any new invention over the existing state of the art.

By placing each 'burner in-or over a sepa- 'over the b-urner compartments insures the rate burner compartment and having an independent air inlet door 3 for each compart ment I am enabled to control the exact amount of air received 'by each burner and to shut off the air to those compartments not being used. This enables me to fulfil the important and generally neglected requirement that,l there s-hall` not be a large surplus ofy air supplied. .This surplus Vair cools the interior surfaces of the boiler or furnace and absorbs heat and carries it up the chimvadvantages as hereinbefore noted.

The frame or wall around chambers A, B, C and the lower portion of the furnace is made' up of side plates 63y held together by end plates 30 and 44, floor plate 32, center division wall 33 and pan P. Upon this wall ,is placed the. heater D, bolted or riveted together.

the whole being The combustion chamber has heat resisting linings 35, 62 and 34. Door 29 gives access to the combustion chamber, grates, and burners. The

grates. The said burners also have flanges individual burner compartmentsoB, B and B are formed by inserting partitions or division plates 27 between them and which are preferably made of'a hard, compressed mixture of asbestos and Portland cement.. This does not warp, corrode or expand appreciably Iunder the heat.- y 'Y The construction of the burners and mixers` is best shown in vertical longitudinal section 4in Fig. 6, in transverse section Fig. 2 'and in plan by Fig. 3. A perspective view of the burner is shown by Fig. 4.- A

Referring. particularly to Fig. 6 the burner consists substantially of a hollow elongated box-shaped member or part having .a number of perforated projections or jet nozzles in its top through which the gas J escapes under more or lessvpressure. The said burner rests upon ledges 54 and 55 at its ends and can be removed by simplylifting it out after first having removed the 14 at their ends added to.center the burners in their compartments so that they properly seat onto themixing tubes and maintain a` f and has a 'flange 53 to fit between the above concentric rings of the burner which with the. interposed packing makes a practically gas tight connection. By thus placing an annular recess 1n the burner instead of on the mixer, it casts easier and cannot become Alled with ashes.

A'rod 9 running transversely through the furnace passes through lugs 56 (see Fig. 6) on the inner end of the mixing tubes and supports the same in working position,

. screws serving to fasten said parts together. The ends of said rod project 'through the first -or lower outer wall or casing of the furnace. Lugs 13 and 14 on the top of the burner support the grate and prevent it from sagging under the intense heat. Perforated lugs 12 and 15 in the grate and burner respectively lare for the purposeof lifting them out by means of the lifter Fig.

5. This lifter has a projection 70 which is wood or other solid fuel. The lowering of the grate gives a correspondingly greater depth of firepot which is required for solid fuel. The removal ofthe burners also allows a more copious draft as'required by solid fuel as well as preventing clogging up of the burner openings whichwould occur if they remained in place. Vhen the grate is so placed a disk 11 cast into the same covers the mixer opening at the top so that no ashes can fall into it. A rotatable tube 8 set into the front wallv of the furnace about the front end of mixer tube 7 is adapted to close the air inlet holes. or openings 66.

Two equivalent and alternate ways of controlling the doors 3 are shown. In both of these Va rod 4 is connected to lugs 26 on the door and passed through the front frame where the gate may be controlled.

The first discloses an index plate 37 on the front frame, see Fig. 3. The outer end of said rod'is bent at right angles to this plate `37 and the position of this bend indicates on -Figsn 6 and A7.

the said index plate the position of the door 3,inrelat ion to its opening.

The other or alternative way is shown in In this latter case the said rod is connected to the gasvalve 1S so that the handle of this actuates the air supply door as well as the gas supply. Tn the illustration given a plug gas valve 18 is used, the plug having an elongation 61 on which a lever 19 is secured by means of nut 59 or otherwise.Y To this lever 19 the rod 4 is attached. The closed position is shownfand both air and gas supplyv are shut off. By opening the gas valve 18, the lever 19 is caused to push on rod 4 which opens the gate 3. The friction of the said valve will hold the gate in any position. With this arrangement when burning solid fuel the air draft supply is controlled either through ash door 31 or by having a main gas valve at 69, Fig. 3, which can then be turned olf 'the gas valve lever 20, Fig. 7.

and the air supply controlled by means of it will be noted that the pivot point of the gate 3 is a little above the middle thereof, Fig. 1, so

adapted to enter holes in the lugs, when they.

can readily belifted out even when red hot.

The toe 7 1 and the heel 72 on the lifter prevent the burner or the projection 70.'

lin case the gas supply gives out or if for any other reason it, is desired to burn solid fuel alone, the grate and burner are lifted.`

gra-te -from rotating on out and removed and then the grate is restored but seated `down on the shelves` 54. and 55` previously occupied by the bur-ucr. Then the furnace is ready to burn coal or that it is in a sense a butterlyvalve. This is the preferred construction as two streams of air then flow into the burner, the one below the gate being thrown `well toward the front and the upper one supplying the rear end of the burner. The distribution of the air supply is therefore even, which is im` port-ant. `The gate 3 is made heaviest at the top so as to counterbaiance in all positions.

The gas shoots into the mixer through nozzle 16, Fig. 6, which is av piece of pipe having a drilled screw plug 17 at its end and the other end is screwed into the v`alve casing. The rotatable sleeve 8 over the outer portion of the mixer tube 7 so made that a quarter turn thereof closes the'opening 66 through or in the sidev of `mixer tube 7.

v'Olne end of this sleeve as Well as of the mixing tube projects out through the casing or Wall of the/ furnace, and the outer end of said sleeve has a'flan'ge 57 with a finger or index 21 to indicate the condition of the mixer openings 66 as to being open or closed. A projecting plug 58 facilitates rotating this sleeve, and a set screw 74, Fig. 8, may be used to fix the adjustments thereof although ordinarily the friction is sufficient. Lugs 22 and 23 limit the rotation of said sleeve 8. A Washer 65 holds the sleeve in place, the valve 18 bearing against said Washer.

The valves 18 are each connected to a pipe 24 running across the front of the furnace, Fig." 7 and Which is supported -by brackets,

25 Which are bolted to the front end of the furnace. By unbolt-ing'these brackets the' pipe 24, valves 18 and nozzles 16 can all `be pulledl out from the furnace as one unit. The sleeve 8`can then be Withdrawn and byfirst removing the rod 9 and lifting outA the grates., I Acan remove the mixing partitions 27, Which latter are burners and tubes 7 and guided in lugs, etc. on the frames 30 and 33.

A door 31 allows the removal of-theashes from all theburner compartments, Gas

may beturned on Whilegburningsolid fuel i `the gas is turned so yasl to ignite same or assist in'its combus- .tion the leakage about the disk 11 being sufficient to afford a lighting flame, said-disk beingla rough casting which does not make a close orgas tightfit.A In each` side of the,

burners there is a hole-73, Fig. 4. When the burners are all in place, these holes are opposite those of adjacent burners, and, When on, a jet shoots out from these holes, there being a corresponding hole 27 so that the jets `of The purpose one burner is lighted it'will automatically light an adjacent burner when the gas has been turned on and so on across the series. This is done gradually and Without. puff if the proporL tions are right gradually. 'j t A pilot light is purposely omitted from this 'system and the user is simply required to open the door 29 to ignite the burners, thus avoiding danger ofexplosiondue .to

andA the gas is 4turned on leakage of gas into1 the combustion chamber previous to igniting.

The door-29 extends entirely across the front ofthe furnace so that any explosion occurring due to Vleakageorescape as above mentioned is unconfinedrand can therefore y do no great damage when lighting occursj' The chances-are that anyydangerous mixture yto of air into the mixer, means outside of said furnace to Jcontrol the air supply Within the furnace and an index indicating the amount of air opening `of said mixer.

2. In a furnace, a series of burner compartments each having separately and eX- ternally controllable air inlets, in combinatrollable mixer, an air supply chamber communlcatlng with each of said burner com- I tion with a mixer in each compartment takpartments through externally and individu'- ally controlled openings, andimeans Whereby the airis heated in the air supply chamber.

dividual chambers vtherefor having partitions betWeen them, said ychambershaving a small Haine opening on each side of each burner, and said partitions provided With holes opposite the said flame openings, so that the said iiames may meet and ignite adjacent burners. v

5. In a furnace, a, chamber having a burner and below it an externally controllable air Iinletto thechamber and Without the furnace a valve controlling the fuel supply to the burner and" means for connecting the said airinlet control tothe said fuel control valve so that'the air inlet is opened With and at the same time as the fuel supply and the air inlet opening being in proportion tohthe fuel supply. opening. 6. A,f\urnace having aseries of bulner compartments provided with separate' controllable air inletsat their rear and an airl supply chamber locatedbehind inIk combination with means for preheating the air in sai-d chamber 'by thev outgoing products of combust trolsaid inlets.

ion, and dampers to con- 4. lIn a furnace, aseries of burners and in-` said inlets,

In testimony 'whereof I aiiix my' signature in the presence of two Witnesses.

OTTO KUENHOLD.

Witnesses: R. B. MOSER, F. I/IVIUSSUrL 

